1 /*
2 * arch/mips/dec/decstation.c
3 */
4 #include <linux/config.h>
5
6 #define RELOC
7 #define INITRD
8 #define DEBUG_BOOT
9
10 /*
11 * Magic number indicating REX PROM available on DECSTATION.
12 */
13 #define REX_PROM_MAGIC 0x30464354
14
15 #define REX_PROM_CLEARCACHE 0x7c/4
16 #define REX_PROM_PRINTF 0x30/4
17
18 #define VEC_RESET 0xBFC00000 /* Prom base address */
19 #define PMAX_PROM_ENTRY(x) (VEC_RESET+((x)*8)) /* Prom jump table */
20 #define PMAX_PROM_PRINTF PMAX_PROM_ENTRY(17)
21
22 #define PARAM (k_start + 0x2000)
23
24 #define LOADER_TYPE (*(unsigned char *) (PARAM+0x210))
25 #define INITRD_START (*(unsigned long *) (PARAM+0x218))
26 #define INITRD_SIZE (*(unsigned long *) (PARAM+0x21c))
27
28 extern int _ftext, _end; /* begin and end of kernel image */
29 extern void *__rd_start, *__rd_end; /* begin and end of ramdisk image */
30 extern void kernel_entry(int, char **, unsigned long, int *);
31
memcpy(void * dest,const void * src,unsigned int count)32 void * memcpy(void * dest, const void *src, unsigned int count)
33 {
34 unsigned long *tmp = (unsigned long *) dest, *s = (unsigned long *) src;
35
36 count >>= 2;
37 while (count--)
38 *tmp++ = *s++;
39
40 return dest;
41 }
42
dec_entry(int argc,char ** argv,unsigned long magic,int * prom_vec)43 void dec_entry(int argc, char **argv,
44 unsigned long magic, int *prom_vec)
45 {
46 void (*rex_clear_cache)(void);
47 int (*prom_printf)(char *, ...);
48 unsigned long k_start, len;
49
50 /*
51 * The DS5100 leaves cpu with BEV enabled, clear it.
52 */
53 asm( "lui\t$8,0x3000\n\t"
54 "mtc0\t$8,$12\n\t"
55 ".section\t.sdata\n\t"
56 ".section\t.sbss\n\t"
57 ".section\t.text"
58 : : : "$8");
59
60 #ifdef DEBUG_BOOT
61 if (magic == REX_PROM_MAGIC) {
62 prom_printf = (int (*)(char *, ...)) *(prom_vec + REX_PROM_PRINTF);
63 } else {
64 prom_printf = (int (*)(char *, ...)) PMAX_PROM_PRINTF;
65 }
66 prom_printf("Launching kernel...\n");
67 #endif
68
69 k_start = (unsigned long) (&kernel_entry) & 0xffff0000;
70
71 #ifdef RELOC
72 /*
73 * Now copy kernel image to it's destination.
74 */
75 len = ((unsigned long) (&_end) - k_start);
76 memcpy((void *)k_start, &_ftext, len);
77 #endif
78
79 if (magic == REX_PROM_MAGIC) {
80 rex_clear_cache = (void (*)(void)) * (prom_vec + REX_PROM_CLEARCACHE);
81 rex_clear_cache();
82 }
83
84 #ifdef CONFIG_BLK_DEV_INITRD
85 LOADER_TYPE = 1;
86 INITRD_START = (long)&__rd_start;
87 INITRD_SIZE = (long)&__rd_end - (long)&__rd_start;
88 #endif
89
90 kernel_entry(argc, argv, magic, prom_vec);
91 }
92